The catalyst that we are using will be a ruthenium nanoparticle catalyst supported on activated carbon. Specifically, we will use a ruthenium on CTC-120 catalyst.
Catalyst Preparation[]
This section will introduce how the catalyst we have decided to use is prepared. The proceeding procedure is required to produce 2.5% ruthenium on CTC-120 catalyst.
- A solution consisting of RuCl3xH2O with deionized water is mixed.
- The solution is then poured into CTC-120 (CALGON Carbon CTC support) in 1 to 2mL aliquots after the solid has dissolved. The aliquots should be allowed to be absorbed by the carbon support.
- The carbon support should be rolled around for approximately 5 minutes.
- The carbon is then dried in a vaccuum oven for about 12 hours.
- The dried carbon is then placed in a tube furnace with argon, and reduced with pure hydrogen by exposure. From 120ºC, the temperature is increased by 0.5ºC per minute until it reaches 400ºC and kept constant for approximately 9 hours.
- After reduction, the catalyst is passivated in 2% oxygen to produce an oxidized metal layer.
- The catalyst is thus stored in its oxidized manner, and is activated with hydrogen reduction.
Catalyst Size & Cost[]
The catalyst is placed on activated carbon beads that are approximately 7.1 mm in diameter.
The cost of ruthenium base metal is approximately $59/oz at present which we then used to calculate the price of the finished catalyst. We estimated that the bulk cost of our catalyust would be approximately 6,100 $/MT. We have also assumed that we will be able to sell any purged catalyst or catalyst silt for its value in Ruthenium - i.e. subtract it's production cost and activated carbon cost - for a rough approximation.
Catalyst Lifetime and Deactivation Mechanism[]
The catalyst has been found to slowly deactivate over the period of about 41 days. When the catalyst decreases in activity the conversion will also decrease, but more importantly the selectivities can vary widely foir our system. In order to maintain product quality we found it necessary to develop a continuous catalyst regeneration system.
The mechanism by which the catalyst deactivates is by becoming coated with the carbophydrate material in the reactor. In order to clean the catalyst and maintain its activity the catalyst must be washed with dilute hydrochloric acid. We have assumed that the washing fluid is dilute enough to have negligible catalyst demetalisation - this was confirmed by one of the patents that we had found.